Genomic insights into a colonization-infection progression by a carbapenemase-producing Klebsiella quasipneumoniae K1 serotype.

OBJECTIVES

This study aimed to elucidate the genomic background of a carbapenemase-producing Klebsiella quasipneumoniae subsp. similipneumoniae that colonized and infected a patient during hospitalization.

METHODS

The isolates recovered from a surveillance swab (isolate CV39) and a subsequent surgical site infection (isolate 415/18) in the same patient were identified, and antimicrobial susceptibility was tested. Biofilm production and genome restriction typing (XbaI-PFGE) were subsequently performed. Last, the first isolate obtained was whole-genome sequenced (WGS) using the MiSeq platform, and online tools were applied for bioinformatic analysis of the relevant information.

RESULTS

Both CV39 and 415/18 were categorized as multidrug-resistant, they exhibited low biofilm production ability, and presented a high genetic similarity (92.9%) by XbaI-PFGE typing. In view of this, the first isolate was submitted to WGS, which demonstrated that CV39 belonged to the sequence type ST138, expressing the K1 and O5 serotypes. Moreover, it presented genes codifying resistance to all beta-lactams, fosfomycin, fluoroquinolones, and quaternary ammonium compounds, as well as virulence systems comprising fimbriae, iron uptake, and immune bypass. Despite four plasmid incompatibility groups being detected, the IncM1 was identified as responsible for the blaKPC-2 mobilization. Finally, the CV39 genome is closely related to other ST138-K1-K. quasipneumoniae strains isolated around the world.

CONCLUSIONS

These results revealed the potential of a colonization scenario by a KPC-2-producing K1 K. quasipneumoniae in progressing to an infectious process in an impaired patient, which may help programs intended to combat antimicrobial resistance.